Multiple primary malignancies in renal cell carcinoma

PURPOSE: We determine the incidence and nature of multiple primary malignancies in patients with renal cell carcinoma, and whether these patients have an increased risk of a second primary malignancy. MATERIALS AND METHODS: Between July 1989 and January 1997, 551 patients underwent an operation for renal cell carcinoma. The incidence of other primary malignancies was determined and classified as antecedent, synchronous or subsequent. The observed number of subsequent malignancies after diagnosis of renal cell carcinoma was compared to the expected number based on age, race and sex specific 1990 to 1994 incidence rates from the United States Surveillance, Epidemiology and End Results data using the Poisson test. RESULTS: The number of primary malignancies, including cutaneous malignancies, was at least 1 in 148 patients (26.9%), at least 2 in 34 (6.2%), at least 3 in 6 (1.1%) and 4 in 1 (0.2%). Other malignancies were antecedent in 85 cases (45.0%), synchronous in 74 (39.4%) and subsequent in 30 (16.0%). The most common other primary malignancies were breast, prostate, colorectal and bladder cancer, and non-Hodgkin's lymphoma. Only men with renal cell carcinoma had an increased risk of bladder cancer (standardized incidence ratio 4.3, p = 0.0067). CONCLUSIONS: Breast, prostate, colorectal and bladder cancer as well as non-Hodgkin's lymphoma were the most common other primary malignancies. Men with renal cell carcinoma have an increased risk of subsequent bladder cancer.